Repair of peripheral nerves with the use of PCL and carbon nanostructures

Author(s)

Kyl Assaf

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2014-01-12

Examining board members

Alexandre Leite Rodrigues de Oliveira; Cecília Amélia de Carvalho Zavaglia; Arnaldo Rodrigues dos Santos Junior

• Advisor: Eliana Aparecida de Rezende Duek; Alexandre Leite Rodrigues de Oliveira

Abstract

Injuries to peripheral nerves generate proximal and distal stumps, usually making end-to-end neurorrhaphy impossible. In such cases, autologous grafts are widely used, but have some disadvantages, such as availability of donor tissue, formation of painful neuromas in the donor area, etc. The tubulization technique, in which tubes are used to guide and protect the nerve during regeneration, offers advantages such as preservation of the donor nerve area and the possibility of manipulating the internal environment of the tube. Many aspects of the conduit to be used for nerve regeneration must be considered as biocompatibility, biodegradability, degradation time, etc. The poly (?-caprolactone) (PCL) is possesses most of these properties. Carbon nanotubes and graphene also have features that make them excellent devices for neural implants and to constitute polymer composites. In this work, sciatic nerves of Lewis rats were transected and tubulized with PCL, PCL with carbon nanotubes (NT1), PCL with graphene oxide (NTN) and PCL with both nanostructures. Nanocomposites characterization showed that nanoparticles have good dispersion, do not alter the degree of PCL crystallinity, provide reinforcement of the polymer matrix and cause changes in the molecular mobility in the amorphous part of the polymer. In the analysis of the prostheses by scanning electron microscopy, NT1, NTN and its mixture showed higher number of adhered cells as compared to the PCL. All materials were also biocompatible. The counting regenerated nerve fibers and comparison of the nerve areas, the mixture showed statistical differences when compared to the other experimental groups (p <0.05). Nevertheless, morphometric analyzes were not different among groups. Furthermore, functional evaluation of the animals showed no significant gait recovery after 8 weeks post surgery. However, comparison of the weigth of the soleus and anterior tibialis and the histological analysis revealed absence of atrophy and preservation of the tissue, indicating a successful reinervation (AU)

• FAPESP's process: 12/08251-0 - Repair of peripheral nerves with the use of PCL and carbon nanostructures.
• Grantee: Kyl Assaf
• Support Opportunities: Scholarships in Brazil - Master